Hot Tropical Plants in Containers

Sunday, September 15, 2002

Tropical plants belong on every deck, patio, and sun porch. These fast growing, bold textured beauties set a sunny mood that welcomes your guests to summer’s outdoor lifestyle. Choose from these popular favorites, or grow them all and make your deck a tropical paradise.

Green and grand: palm trees and fatsia japonica

Even where light is limited by trees or structures, use these glossy green leaves to brighten things up. Parlors, sagos, and other popular palms grow slowly, so buy a big one to be the centerpiece of your collection. Grow these on the dry side, watering only when the top inch of soil feels dry to your touch. Fertilize four times each year with a slow release formula. Fatsia japonica offers a profusion of avocado-colored, maple-shaped leaves that swell to a foot across as they turn dark green. Fatsia drinks heavily, so add more peat moss to its soil mix. You won’t have to water as often.

Sweet to smell: citrus and sweet olive

Grow these two small trees on a sunny warm patio and when they bloom, open the window and let the fragrance drift indoors. Citrus, especially lemons and kumquats, adapt readily to container culture. Tip prune each year as you make preparations for overwinters. Cut out branches that fail to bloom for two years to new growth coming for future flowers. Sweet olive (Osmanthus fragrans) is an old fashioned evergreen with perfumey flowers in cool weather. Whitefly can be a problem on both; use a light oil spray in winter or an insecticidal soap with pyrethrin to control the population.

Tropic’s grand dames: hibiscus and ferns

With just these two plants, your deck positively screams, "Tropical holiday!" Shiny leaves and trumpet shaped flowers cover hibiscus, and the popular treeform adds height to your container garden. Take cuttings of hibiscus frequently to keep growth compact; root them in sand and compost. Boston Fluffy Ruffle, or Fishtail, all our favorite ferns can look rough after a season or so; invigorate by cutting back. Trim nearly all the top off, split the rootball in half, score on four sides. Soak in fish emulsion before repotting.

Flowers and fruit: cannas and bananas

On a warm July evening, you’d swear you can hear these plants growing. Look for dwarf cannas for faster flowers, but don’t miss larger ones, especially ‘Tropicana’, a bawdy babe with clown-striped leaves. If leaves don’t uncurl like they should, suspect canna leaf rollers and dust with diatomaceous earth or sevin dust. Banana plants reach for the sky; give them a large pot in a big spot to grow. Water both these plants daily in hot weather and fertilize at least once a month.

Vigorous vines: mandevilla and sweet potatoes

Vines deliver tropical texture with waxy leaved mandevilla and sharply serrated ornamental sweet potato, ‘Blackie’. Mandevilla needs a trellis, and its bright pink flowers look great against redwood lath. ‘Blackie’, and the chartreuse ‘Marguerite’ can spill down the wall from baskets or crawl over any open space. Both plants will benefit from a systemic insecticide at the first sign of trouble, as their appealing succulence can make for fast growing insect infestations.

When autumn’s chill threatens the tender tropicals, make a nest for them in a sunny room, heated garage, or utility room if you don’t have a greenhouse. All it takes to keep them happy is temperatures above forty degrees, and enough light to read a newspaper by. The more light and warmth you can provide above that, the more water and fertilizer they’ll need to support more active growth. If you want to add light, consider putting a grolight bulb in a nearby lamp. Or add a two lamp flouresecent fixture, one a cool white type, the other a daylight spectrum. For additional heat, you can use bales of hay around a cluster of pots, small electric heaters, or incandescent lights. Put a thermometer among your plants.

Pick a pot that suits your style.
clay pots: great to look at, best to use if you like to water frequently
plastic pots: durable and colorful, use these if you’re likely to forget watering for several days each week
reservoir pots: add water to reservoir only as needed, great for travellers

This is the unedited version of an article that appeared in Garden Almanac, a publication of GroGroup.